Home :: Agar

Agar - Uses And Side Effects

A jelly-like substance, agar comes from various species of red marine algae, including Gelidium cartilagineum and Gracilaria confervoides. Bacteriologists use agar as a culture medium, and some herbalists recommend it as a laxative. Many pharmaceutical and food products contain agar as an emulsifying and suspending agent.

Nutrient agar is used throughout the world as a medium for the growth of bacteria and fungi, but not viruses. Though less than 1% of all existing bacteria can be grown successfully, the basic agar formula can be used to grow most of the microbes, whose needs are known. More specific nutrient agars are available, because microbes can be picky. For example, blood agar, which is generally combined with horse blood, can be used to detect the presence of haemorrhagic micro-organisms such as E.coli O:157 H:7. The bacteria digest the blood, turning the plate clear.

Common doses of Agar

Agar comes as dry powder and in flakes and strips. Some experts recommend the following dose:

• As a bulk-forming laxative, 4 to 16 grams taken orally once or twice daily.

Uses of Agar

• Constipation
• High bilirubin in newborns

Side effects of Agar

Call your health care practitioner if you experience any of these possible side effects of agar:

• abdominal pain
• chest pain or tightness
• choking (from taking agar without enough liquid)
• difficulty swallowing or breathing
• vomiting

• decreased absorption of vitamins, minerals, and nutrients (especially calcium, iron, zinc, copper, chromium, and cobalt)
• obstruction of the bowel or esophagus.

Interactions

Combining agar products with certain drugs may alter their action or produce unwanted side effects. Don't use agar while taking:

• electrolyte solutions
• products that contain alcohol or tannic acid.

Important points to remember

• Don't use agar if you're pregnant or breast-feeding.
• Avoid agar if you've had throat problems, difficulty swallowing, or bowel or esophageal obstruction.
• Take agar products on an empty stomach to improve vitamin and mineral absorption from foods.

What the research shows

No long-term studies have evaluated agar's effects on mineral and nutrient absorption in people. With more effective bulkforming laxatives such as psyllium available, medical experts see no need to use agar to treat constipation.

Other names for Agar

Other names for agar include agar-agar, Chinese gelatin, colle du japon, E406, gelose, Japanese gelatin, Japanese isinglass, lay or carang, and vegetable gelatin.

Products containing agar are sold under such names as Agarbil, Agoral, Agoral Plain, Demosvelte-N, Falqui, Lexat, Paragar, and Pseudophage.